Method of producing interchangeable letter or figure dies.



UNITED STATES Patented July 5, 1904.

PATENT OEEicE.

GEORGE WHITE, OF JERSEY CITY, NEW JERSEY, ASSIGNOR, BY MESNE ASSIGNMENTS, TO THE EN GRAVING MACHINE COMPANY, A CORPORA- TION OF NEWV YORK.

METHOD OF PRODUCING INTERCHANGEABLE LETTER OR FIGURE DIES.

SPECIFICATION forming part of Letters Patent No. 764,170, dated July 5, 1904.

Application filed November '7, 1903. Serial No. 180,154. (No model.)

To (all whom it may concern:

Be it known that I, GEORGE TVHITE, a citizen of the United States, residing in Jersey City, in the county of Hudson, in the State of New Jersey, have invented certain new and useful Improvements in Methods of Producing Interchangeable Letter or Figure Dies, of which the following is a specification, reference being had to the accompanying draw- IO ings, forming a part hereof.

In the preparation of plates or blocks for printing in which plates or blocks the letters or other characters are sunk by dies so that the plates or blocks may thereafter be used like plates engraved by hand it has been proposed heretofore to provide a block or bar of relatively soft metal and of such dimensions as to receive thereon side by side a number of letters or figures, to roll such block or bar upon a previouslyprepared hard plate in which the letters or other characters have been sunk, as by hand-engraving, and by such rolling to transfer the characters to the face of the block or bar, then to cut the block or bar 2 5 into separate letter or figure dies, so that they may thereafter, when hardened, be assembled to form the desired word or number and by rolling be transferred in intaglio to the surface of the plate which is to be used for print- 3 ing. In some instances the method thus described has been found unsatisfactory for the reason that after cutting the block or bar to form the separate dies it was difificult to secure the desired degree of accuracy in the grinding, particularly of the sawed surfaces.

It is the object of the present invention to provide a method by which the objection alluded to shall be avoided and greater accuracy of the finished dies be attained with less dif- 4 ficulty.

The invention will be more fully described hereinafter with reference to the accompanying drawings, in which Figure 1 is a plan View of a plate having engraved thereon in intaglio a character to be reproduced. Fig. 2 shows perspective views of several individual blocks adapted for letters of different widths. Fig. 3 is a view in elevation of a chuck or holder in which each individual letter-blockmay be held while the 5 desired character is being formed on its surface. Fig. 4 is a section on the plane indicated by the line 4 4 of Fig. 3. Fig. 5 is a view in perspective of the completed die.

In the practice of the improved method the 5 5 plate A (shown in Fig. I) has engraved thereon, preferably while it is in a relatively soft condition, the desired printing character in intaglio and is then hardened, if it is not already sufiiciently hard, to endure the subse- 6O quent operations. From a number of blocks B, each adapted to form a single-letter die, the blocks being formed of diflerent standard widths to accommodate letters of different widths, there is selected one block of suit- 5 able width and the same is placed in a chuck or holder C. Each block B is of relatively soft metal and is of no greater size than will permit it to be securely held in the chuck or holder during the subsequent operations. 7 One surface is curved concentrically With the axis of rotation of the chuck or holder, and the depth of the block is such as to permit such curved surface to stand slightly above the surface of the chuck or holder when the block is properly seated therein. The chuck or holder is then placed in a suitable apparatus and is rolled under great pressure in contact with the surface of the plate A, so that the letter or other character which is formed on such plate A in intaglio is transferred to the exposed surface of the block B in relief. when the character has been formed upon the surface of the block B, the latter is hardened, preferably being case-hardened only as to the surface upon which the character has been formed. After the hardening'the block is ground to correct any distortion which may have taken place in the hardening operation and to reduce the Width of the block from 9 the standard width to a width corresponding more exactly with the width of the letter or other character formed on the block. It is' found that in the grinding the separate block, formed as described and having the desired character rolled upon its surface, is ground.

to the desired degree of accuracy much more readily than is possible with a block sawed from a larger block or bar after the letters or other characters have been formed thereon. It Will be understood, of course, that during the grinding the block is held in a special chuck provided for the purpose. When the several blocks have been prepared in the manner described, those blocks are selected Which are necessary to form the desired Word or number and are assembled in proper order in' another chuck or holder by Which they are securely held While being rolled upon the surface of a relatively soft plate to transfer thereto in intaglio the desired Word or number. The plate or block thus prepared may then be used for printing in the same manner as an engraved plate or block.

I claim as my invention The method of producing interchangeable letter or figure dies Which consists in providing a series of relatively hard plates each having a letter or figure sunk therein, providing a series of blocks of relatively soft metal, each block being of suitable dimensions to receive a single letter or figure and having a curved face, mounting each of such blocks separately in a chuck or holder With the axis of the curved face coinciding With the Working axis of the chuck or holder, transferring each of such letters or figures separately from the face of the plate to the face of a block in relief, hardening each separate block With a single character thereon, and grinding each separate block to give true surfaces, so that the several blocks may thereafter be assembled for the Word or number desired, substantially as described.

This specification signed and witnessed this 31st day of October, A. D. 1903.

GEORGE WHITE. In presence of FRANK J. HIGGINS, D. E. WHITE. 

